• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2007년도 추계학술발표회
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• pp.57-60
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• 2007

북방한계선 주변의 한강하구는 지난 60년 동안 개발 및 이용이 금지되었기 때문에, 자연하천의 모습을 간직하고 있다. 그러나 최근 들어 경인수로를 비롯한 민간 이용을 위한 논의가 이루어지고 있으나, 한강하구의 기본적인 특성에 관한 정보가 부족한 실정이다. 본 연구에서는, 인공위성 합성개구레이더(SAR)를 이용한 하구역 퇴적상의 변동 조사를 실시하고, 퇴적상을 기반으로 한강하구 뱃길을 제안하고자 한다. 2000년부터 2005년까지의 Radarsat-1 영상을 이용하여 시계열해석한 결과에 따르면, 1) 한강 하구역은 집중호우등 에 의해 부유사가 많이 발생하며, 2) 식생역(vegetated area)은 거의 안정화단계에 있으며, 3) 퇴적상(bar)의 월 변동성은 크지 않으나, 매년 발생하는 호우 등에 의해 퇴적상의 위치 변화는 상당히 컸다. 여기서 얻어진 퇴적상의 변동 특성을 기반으로, 북방한계선 이남의 한강 수역에 대한 뱃길의 설계 방향을 제시하였다. 향후, 장기간에 대한 위성 및 현장 조가를 바탕으로 자연하천의 특성을 훼손하지 않는 범위에서의 개발이 이루어져야 한다.

• Animal Bioscience
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• 제36권7호
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• pp.1075-1082
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• 2023

Objective: Animal feed companies and researchers are currently embarking on quests for feed additives that could combat the pathogens while promoting growth as well as maintaining quality products. The current study aimed to evaluate the effects of onion extracts on growth performance, carcass quality, and bone morphometrics of broiler chickens. Methods: A total number of 200 one-day-old unsexed Ross 308 broiler chicks were assigned to 5 treatment groups, replicated 4 times. Each replicate (pens) held 10 chickens in a completely randomized design. The experimental diets were then randomly allotted to the pens which act as experimental units. The isoenergetic and isonitrogenous diets were formulated by including onion extracts at 0, 5, 10, 15, or 25 g/kg in a complete broiler diet. Feed intake, and body weight, were recorded then used to calculate feed conversion ratio. At the end of the experiment (42 days), four chickens from each pen were randomly selected for slaughter for carcass, bone morphology and sensory evaluation. Results: Results showed that onion extract supplementation did not affect (p>0.05) growth performances and meat sensory evaluation. However, there was a significantly increased (p<0.05) meat shear force in groups receiving onion extracts dietary treatments. Furthermore, onion extracts improved (p<0.05) bone morphology of broiler chickens in terms of weight, diameter, calcium, and phosphorous contents. Conclusion: In conclusion, onion extracts can be safely included in a commercial broiler diet as a growth promoter without causing adverse effects on growth performance traits and carcass quality in chickens. Onion extract supplementation improved tibia bone growth and strength in broiler chickens.

• 한국정밀공학회지
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• 제11권6호
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• pp.185-199
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• 1994

This study has been performed to present a new automatic tool wear measurement by digital image processing. The purpose of this paper is to develop an automatic tool wear measuring system based on the image processing which can be applied to the quasi-real time measurement of the characteristics of insert tip in turning. Tool wear monitoring is one of the key-problems, for the development of control systems of modern unmanned factory which are not completely solved now. In oredr words at present complete qualitative and quantitative information on tool wear morphology is required, at least on the following aspects : flank wear, its dimensions and distribution on the maximum and mean values on VB pqrqmeter in the various zones of the wearland. crater wear, its main dimensions and values of KT parameters. This research has been performed to this technique made possible by designing a proper lighting system to the worn tool with following features : The flank wear is measured by observing the active cutting part from a proper direction and by lighting the wearland by a diffuser optic system. The crater wear is visualized by lighting the tool by a He-Ne gas laser system developed in this study. By means of this system it is research to evaluate classical parameters of tool wear and to have complete information about tool wear morphology.

• Reproductive and Developmental Biology
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• 제35권3호
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• pp.257-263
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• 2011

In general, the blood cell culture is a common method for animal chromosome preparation. However, every animal and its cells have unique physiological characteristics and functions. Hence, it is very difficult to find the suitable method of chromosome preparation using animal lymphocyte culture. This study was carried out to fine the suitable method of chromosome preparation using lymphocytes cultures in mammalians and aves including cattle, rat, mouse and chicken. To seek the optimal method of lymphocyte culture in each animal, $2^3$ factorial experiment was designed. The design evaluated three main effects in culture duration, kinds of mitogen supplements and colcemid exposure time with two levels within each effect. The mitotic index and the score of chromosome morphology were analyzed. In results, the suitable methods of lymphocyte culture for chromosome preparation were 72 hours culture, pokeweed mitogen(PWM) supplement and 90 minutes of colcemid exposure in cattle, 72 hours culture, PWM supplement and 50 minutes of colcemid exposure in chicken, 96 hours culture, concanavalin A supplement and 90 minutes of colcemid exposure in rat, and 72 hours culture, PWM supplement and 50 minutes of colcemid exposure in mouse, respectively. In conclusion, kinds of mitogen, culture duration and colcemid exposure time significantly affected the mitotic index and chromosome morphology, in animal lymphocyte culture. The interaction effects between/among treatment factors were also statistically significant.

• Elastomers and Composites
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• 제34권5호
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• pp.407-413
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• 1999

비세라믹 복합절연소재는 기계적 물성, 환경문제, 대량생산과 용이한 설계등의 우수한 특성으로 인해 전력산업분야에서 관심의 대상이 되어왔다. 또한 세라믹 절연체에 비하여 가볍고, 더욱 강인한 물성을 가진다는 장점이 있다. 본 연구에서는 뛰어난 전기 절연 특성과 우수한 내열, 내산화, 내오존성과 내후성을 가진 ethylene propylene diene monomer(EPDM)를 절연소재로 사용하였다. 특히, EPDM은 다른 고무 복합체에 비해 우수한 소수성을 가지기 때문에 장기간 사용이 가능하다는 점에서 본 연구에서는 EPDM 복합체의 유변학적 물성, 전기적물성, 그리고 접촉각의 측정을 통한 소수성 및 회복력에 관한 연구를 하였다. 또한 SEM을 사용하여 표면 형태학적 연구를 수행하였다.

• 한국분말재료학회지
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• 제8권3호
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• pp.197-200
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• 2001

Modified inert gas condensation method was used to produce the nanocluster composites of $CuO/CeO_2$. High-resolution TEM, SEM and catalytic measurements have been used to characterize the samples and study the synergistic effect between the CuO phase and $CeO_2$(ceria) support. By varying the He pressure, the heating temperature and configuration of the heating boats inside the modified gas condensation chamber, nanoclusters of varying sizes, shapes and composition can be produced. The composition and nanostructured morphology were shown to influence the catalytic properties of the system. A copper content around 10 at% with a morphology that favors high-energy surfaces of ceria is shown to be beneficial for a high catalytic activity.

• 전자공학회논문지 IE
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• 제48권1호
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• pp.16-24
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• 2011

본 논문에서는 트림 T형 용접너트 생산 시스템 중 불량품을 자동으로 선별할 수 있는 자동 선별기를 비전 검사기를 사용하여 개발하였다. 카메라로부터 입력되는 영상 신호에 대해 히스토그램을 활용한 경계 판별 및 나사산 검출, 이진 모폴로지 연산(Binary morphology operation)을 활용한 얼룩 검출 등의 기법을 활용하였다. 기존의 검사기나 육안 검사에서 불가능하였던 수치 검사를 0.1mm의 정밀도로 검사할 수 있도록 하였으며, 이를 통해 제조단가를 25% 절감하고 생산성을 330% 이상 향상시킬 수 있었다.

• 한국의류학회지
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• 제46권3호
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• pp.481-493
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• 2022

This study investigated process conditions for 3D printing through manufacturing thermoplastic polyurethane (TPU) samples under different infill conditions. Samples were prepared using a fused deposition modeling 3D printer and TPU filament. 12 infill patterns were set (2D: grid, lines, zigzag; 3D: triangles, cubic, cubic subdivision, octet, quarter cubic; 3DF: concentric, cross 3D, cross, honeycomb), with 3 infill densities (20%, 50%, 80%). Morphology, actual time/weight and compressive properties were analyzed. In morphology: it was found that, as infill density increased, the increase rate of the number of units rose for 2D and fell for 3DF. Printing time varied with the number of nozzle movements. In the 3DF case, the number of nozzle movements increased rapidly with infill density. Sample weight increased similarly. However, where the increase rate of the number of units was low, sample weight was also low. In compressive properties: compressive stress increased with infill density and stress was high for the patterns with layers of the same shape.

• Journal of Electrochemical Science and Technology
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• 제15권2호
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• pp.207-219
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• 2024

Metal-N-C (MNC) catalysts have been anticipated as promising candidates for oxygen reduction reaction (ORR) to achieve low-cost polymer electrolyte membrane fuel cells. The structure of the M-N_x moiety enabled a high catalytic activity that was not observed in previously reported transition metal nanoparticle-based catalysts. Despite progress in non-precious metal catalysts, the low density of active sites of MNCs, which resulted in lower single-cell performance than Pt/C, needs to be resolved for practical application. This review focused on the recent studies and methodologies aimed to overcome these limitations and develop an inexpensive catalyst with excellent activity and durability in an alkaline environment. It included the possibility of non-precious metals as active materials for ORR catalysts, starting from Co phthalocyanine as ORR catalyst and the development of methodologies (e.g., metal-coordinated N-containing polymers, metal-organic frameworks) to form active sites, M-N_x moieties. Thereafter, the motivation, procedures, and progress of the latest research on the design of catalyst morphology for improved mass transport ability and active site engineering that allowed the promoted ORR kinetics were discussed.

• 디자인학연구
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• 제5권1호
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• pp.37-44
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• 1992

Today, the art and the architecture face up to the problem of loss of direction. So, the derection of post have been lost. This phenomina cause the second loss of direction, because the mode of pre-modernism is underestimated. After all, the mode and philosophy of after-modernism face up to the new crisis of derection. Present artists, archtectures and designers have to acnieve new trial and study for estimation of aestetics and directions. Ultimately, constant exercise and study of philosophy, morpholophy, morphology, current mode and new materials is necessary to search a methodology. This all have to be accomplished by the clear philosophy. The original identity is formed in environmental basis. So, first, architectures, designers, and artist understand native identity, second, we sho have acadenical and practical faculties impose significance. In case of Europe, the change of mode have led paradigm of culture. The great change of social culture have come out the wave of revolution that cross in design, architecture and art. 1920's of modernism evolve 1960's completion. In the change of life style, functionalism have evolved postmodernnism. But, in this change we do not suggest the new derection that form concrete idea and sympathy. This phenomina appear in the end of a centry, and nowaday is that day. This trends effect on artists, architectures, and designers, and design and will be changed. Finally, we need to study of concrete and new direction in this circumstance.